U.S. patent number 4,554,761 [Application Number 06/616,246] was granted by the patent office on 1985-11-26 for pollinating bag.
This patent grant is currently assigned to Carpenter Paper Company. Invention is credited to Joseph M. Tell.
United States Patent |
4,554,761 |
Tell |
November 26, 1985 |
Pollinating bag
Abstract
A cover for selectively protecting a plant reproductive organ
from pollination. Design features of the invention make it
particularly useful in the hybridization of corn plants. The cover
slips over the shoot of the corn plant when it is in the early
stages of development and is left in place until the shoot is ready
for pollination. The manner of construction imparts a bias to the
cover towards drawing inward, assuring that it will remain in place
during high winds, and allowing for expansion as the shoot
increases in size. The cover is transparent to enable workers to
observe developmental stages. The cover material is vapor permeable
to prevent unwanted condensation from destroying transparency and
to discourage the growth of mildew, fungus and bacteria.
Inventors: |
Tell; Joseph M. (West Des
Moines, IA) |
Assignee: |
Carpenter Paper Company (Des
Moines, IA)
|
Family
ID: |
24468612 |
Appl.
No.: |
06/616,246 |
Filed: |
June 1, 1984 |
Current U.S.
Class: |
47/1.41;
47/24.1 |
Current CPC
Class: |
A01H
1/027 (20210101) |
Current International
Class: |
A01H
1/02 (20060101); A01G 007/00 () |
Field of
Search: |
;47/1.41,26
;383/124,123,125 ;428/138 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hafer; Robert A.
Assistant Examiner: Lewis; Bradley M.
Attorney, Agent or Firm: Henderson & Sturm
Claims
I claim:
1. A plant reproductive organ antipollination barrier cover
comprising:
cover means constructed of a transparent, uncoated, heat sealing,
vented polypropylene film for extending over and around a plant
reproductive organ for selectively preventing said reproductive
organ from pollination, said cover means including:
a front panel;
a rear panel;
first side closure means for sealingly connecting said front and
rear panels along one side thereof, said side means including a
first and second side panel;
first crease means for biasing said first side panel and said rear
wall towards each other;
second crease means for biasing said first and second side panels
towards each other;
third crease means for biasing said second side panel and said
front panel toward each other;
second side closure means for sealing connecting said front and
rear panels along the other side thereof; and
end closure means for sealing one end of said front and rear side
panels and said first and second side means with respect to each
other whereby said one end will be sealed to prevent the entry of
pollen into said one end of said closure means, and wherein said
front wall, rear wall, first side panel and second side panel are
all secured together along a substantially straight seam oriented
transversely with respect to said first, second and third crease
means and wherein said first, second and third crease means extend
to said seam.
2. The cover of claim 1 wherein said second side closure means
includes a third and fourth side panel;
fourth crease means for biasing said third side panel and said rear
wall towards each other;
fifth crease means for biasing said third and fourth side panels
towards each other; and
sixth crease means for biasing said fourth side panel and said
front panel towards each other.
3. The cover of claim 1 wherein said plastic material is a vapor
permeable compound to prevent condensation of moisture from
obscuring the view of the plant reproductive organ covered by the
device, and to discourage the growth of mildew, fungus and
bacteria.
4. The cover of claim 1 wherein one of said front and rear panels
has a notch means disposed therein for permitting easy opening of
said cover means.
5. The cover of claim 1 wherein said seam was formed by heating the
front, rear, first and second side panels while pressing them
together.
6. The cover of claim 5 wherein said one end of said front, rear
and side panels are folded over and glued to one of the front and
rear panels.
Description
TECHNICAL FIELD
The present invention relates generally to equipment used in plant
hybridization, and more particularly to the hybridization of corn
plants.
BACKGROUND ART
Part of the hybridization process involves the protection of the
reproductive organs of a parent plant from unwanted airborne pollen
by covering it at an early stage. After the plant has reached a
sufficient level of development, a worker removes the cover and
pollinates the plant with pollen from another carefully selected
plant. A standard cover in the industry is constructed by folding
and gluing a sheet of white paper to form a thin flat tube, then
folding one end over so that the tube is closed. The standard
design is not biased toward drawing inward, so it is vulnerable to
high winds which tend to blow it off the corn shoot. Care must be
taken in placing and checking the standard cover since it does not
expand easily to allow for the growth of the shoot. It is not
uncommon for the standard cover to burst if the shoot becomes too
large, rendering the plant useless for the purpose of
hybridization. To remedy this, workers are instructed to watch for
covers ready to burst and to loosen them by sliding them upward
one-half to one inch if necessary. This procedure is time consuming
and requires careful observation.
When using the standard paper cover, it is difficult to determine
if the plant is ready for hybridization since the standard cover
device does not permit observation of the shoot within. Therefore,
it may be necessary to sacrifice one or more plants by removing
their covers to observe the stage of development. Once the cover is
removed, airborne pollen from unwanted sources may enter and the
plant is rendered unusable.
A transparent cover from Poland has been used, at least
experimentally. It is analogous in design to the aforementioned
standard in the industry, since it is thin and flattened but
additionally it is formed by sewing two rectangular pieces of
plastic together at three edges. Thus, in its construction, it has
most of the shortcomings of the standard of the industry. The
plastic from which it is constructed is brittle, traps moisture,
fogs easily, and promotes the growth of bacteria and fungi.
Consequently, there is a need for a cover which will remain in
place, expand automatically without bursting, allow for easy
observation of the development of the plant, and will not provide
an environment which encourages the growth of undesirable bacteria
and fungi.
DISCLOSURE OF THE INVENTION
The present invention relates to a cover for selectively preventing
a plant reproductive organ from pollination. The cover includes a
front and rear wall, a pair of folded and creased side walls
sealingly attached to said front and rear walls, with the front,
rear and side walls meeting together at the top, then being folded
over and sealed to preserve an inward crease of the end walls so as
to bias the walls toward drawing inwardly together, yet allowing
for needed expansion.
An object of this invention is to provide a cover for a shoot in a
hybridization process which will remain tightly in place during
high winds, yet is automatically expandable as the plant shoot
grows.
Another object is to obviate the need for the close observation and
adjustment required in the past to prevent bursting of a cover of
the aforementioned type.
A further object of the present invention is to provide a cover
which allows for a clear view of the state of development of a
shoot within the cover.
Still another object is to find a material for shoot covers which
will remain stable, clear and dry even in conditions encouraging
condensation of moisture, which could obscure the view and promote
the growth of bacteria, mold, mildew and fungi.
Other objects, advantages and novel features of the present
invention will become apparent from the following detailed
description of the invention when considered in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cover constructed in accordance
with the present invention as it would look when initially placed
on an undeveloped reproductive organ (shoot) of a corn plant;
FIG. 2 is a perspective view of the cover of FIG. 1 after the shoot
has grown in size and matured, showing the expanded walls of the
cover;
FIG. 3 is a perspective view of the front and unexpanded walls as
the cover appears before or after use thereof;
FIG. 4 is a perspective view of the back, an unexpanded side wall,
and the sealed fold which forms the closed top of the cover as it
appears before or after use;
FIG. 5 is a perspective view of the cover along, shown in an
expanded position;
FIG. 6 is a cross-sectional view of the cover taken along line 6--6
of FIG. 4; and
FIG. 7 is a partial enlarged cross-sectional view of the cover
taken along line 7--7 of FIG. 4 and showing a heat sealed and glued
fold which forms the closed top of the cover.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring now to the drawings wherein like reference numerals
designate identical or corresponding parts throughout the several
views, FIGS. 3-7 show the cover (10) constructed in accordance with
the present invention. The cover (10) is constructed of a
transparent plastic material, specifically an uncoated, heat
sealing, vapor permeable polypropylene film. A front (11), FIG. 3,
has an optional thumb notch (12) for facilitating ease of opening
of cover (10). A back (13), FIG. 4, has a sealed seam (14). The two
sides (15) are folded inwardly to permit controlled expansion, as
best shown in FIG. 6. FIGS. 2 and 5 show the positions of the
folded sides (15) when the cover (10) is expanded. By heating the
cover (10) during the folding process, the creases (16), (17) and
(18) are permanently formed into the cover (10). A first side panel
(20) is formed between creases (16) and (17), and a second side
panel (21) is formed between creases (17) and (18). The opposite
side is identical to the side shown in FIG. 5.
A top (19) is formed, as best shown in FIG. 7, by folding over the
unexpanded cover and sealing the folded top portion (19) with heat
and glue. Note that the folding of the seams (16), (17) and (18) is
preserved during such folding and sealing process. This biases the
walls (11) and (13) towards each other which allows for needed
expansion as the shoot grows and develops. (See FIGS. 1 and 2).
Also, since the cover device (10) is resilient, and because of the
particular folded construction, it will always tend to return to
its original FIGS. 3 and 4 position. This will cause the cover
device (10) to cling tightly to a shoot (22) as shown for example
on corn stalk (23) in FIGS. 1 and 2, whether the shoot (22) is in a
small developing stage as shown in FIG. 1, or in an enlarged, more
developed stage as shown in FIG. 2. This inherent biasing of crease
(17) and walls (11) and (13) toward the shoot (22) prevents the
cover (10) from blowing off of the shoot (22) during high winds or
other outside forces, and yet allows the shoot (22) to expand
without bursting.
The preferred approximate dimensions of the cover parts are as
follows: Sides are 7".times.4". Infolded ends are
triangularly-shaped with a base of 21/2 inches, a height of 7
inches, and folded creases (16), (17) and (18) on each side which
perpendicularly bisects the base and bisects the apex of the
triangle. The top fold, FIG. 7, is 1/2 inch wide. The seam (14) on
the back overlaps by 3/4 of an inch.
The invention is utilized as shown in FIGS. 1 and 2. Firstly, the
cover is slightly expanded and slipped over the immature shoot of
the plant. This prevents pollen from overhead corn tassels from
reaching the shoot until the workers are ready to pollinate the
plant from a specially selected source. The biasing of the cover
(10) holds it securely in place. FIG. 2 shows the matured shoot
(20), which has grown in size from the FIG. 1 size. The folded
sides (15) of the cover have expanded to allow for growth, yet the
inherent biasing forces continue to hold the cover (10) in place
despite changes in the size of the shoot (22). A worker can observe
the condition of the corn silk through the cover (10) to determine
when the plant is ready for pollination. The cover is removed for
the pollination process.
Considerable inventive effort went into selecting the material used
in making the cover, since not all clear plastic materials are
suitable. The cover material must be readily permeable by water
vapor. If not, condensation on the inside of the cover will prevent
observation by causing a moist environment within the cover which
encourages the growth of bacteria, mold, mildew and fungus. Also,
some plastics are adversely affected by sunlight. They yellow,
become brittle and lose their plasticisers at a rapid rate. The
above identified problems have been solved by utilizing an
uncoated, heat sealing, vented polypropylene film of approximately
0.00122 inch in thickness. The material is relatively stiff, but
not brittle, does not fog easily, has good water vapor and oxygen
transmission rates, and has resilient properties.
Many modifications and variations of the present invention are
possible in light of the above teachings. It is therefore to be
understood that, within the scope of the appended claims, the
invention may be practiced otherwise than as specifically
described.
* * * * *